The U.S. State Department has announced that Washington was renewing several sanctions against Iran's nuclear program amid the global coronavirus pandemic.

"The United States is renewing four restrictions on the Iranian regime’s nuclear program for an additional 60 days," State Department Spokeswoman Morgan Ortagus said in a statement on Monday.

Despite reports in the media, U.S. has not yet officially confirmed that some American and foreign businesses were granted waiver extensions to do business with Iran.

According to American political news outlet The Hill, the waiver decision was opposed by Secretary of State Mike Pompeo, but Treasury Secretary Steven Mnuchin defended the necessity of extensions in the wake of heavy criticism the Trump administration has faced.

Iran, China, Russia and a number of other countries have been vocal about the lifting of U.S. sanctions at a time when countries are combating the spread of coronavirus.

Ortagus' remarks came days after Iranian Foreign Minister Javad Zarif blamed U.S. sanctions for Iran's inability to obtain medical supplies to combat the novel coronavirus on Sunday.

Zarif accused the U.S. of "medical terror," tweeting: "This even 'exceeds what would be permissible on the battlefield."

"Iran's continued expansion of nuclear activities is unacceptable. The regime's nuclear extortion is among the greatest threats to international peace and security," she said.

Echoing U.S. President Donald Trump, she stressed that Iran would "never be allowed" to have a nuclear weapon.

Ortagus said the U.S. would continue "to use the full range of diplomatic and economic tools to constrain Iran’s destabilizing proliferation activities" and "closely monitor all developments in Iran's nuclear program."

She added that the current restrictions could be adjusted "at any time."

Last week, the UN High Commissioner for Human Rights Michelle Bachelet called for the easing of sanctions against several countries including Iran, to allow their health care systems to fight the disease and limit the global spread of COVID-19.

Tensions have been escalating between the U.S. and Iran since May 2018, when Trump withdrew from a nuclear pact world powers struck with Iran to curb its nuclear program in exchange for billions of dollars in relief from economic sanctions.

Trump has since embarked on a campaign to scuttle the agreement, including the reimposition of sanctions on Iranian crude oil that were lifted as part of the agreement.

Iran is one of the countries most affected by the coronavirus, with 2,898 deaths due to the virus and positive cases and 44,606 positive cases.

After first appearing in Wuhan, China, last December, the novel coronavirus has spread to at least 178 countries and regions, according to data compiled by U.S.-based Johns Hopkins University.

The data shows more than 788,500 cases have been reported worldwide so far, with the death toll nearing 38,000 and almost 167,000 recoveries.